A drying system of this type for brown coal is known, for example, from EP 0 819 900 A1. The dryer has a dryer chamber in which a heat exchanger unit is arranged. A nozzle bottom arrangement is located below the heat exchanger unit. The dried brown coal is taken out of the dryer chamber below the nozzle bottom arrangement. The nozzle bottom arrangement has two nozzle bottom segments which each have a distributor chamber and nozzle bars connected thereto in a row and located parallel next to one another. The nozzle bars of the two nozzle bottom segments are pushed laterally into the dryer chamber and are located next to one another on both sides of the central longitudinal plane of the dryer. A partition is arranged between the two nozzle bottom segments. A plurality of nozzles for ejecting the fluidizing medium are arranged on each nozzle bar. Purified hydrocarbon vapor is supplied as the fluidizing medium. The introduced quantity of hydrocarbon vapor and the approach flow velocity are controlled in such a manner that a homogeneous fluidized bed is produced in the region above the heat exchanger unit.
Dryers with a nozzle bottom arrangement of the type mentioned at the beginning are also known, for example, from EP 08 19 901 A1 and EP 0 819 903 A1.
Starting from the known nozzle bottom, it can be considered to be the object of the present invention to enable better adaptation of the operating state of the nozzle bottom arrangement to the current operating state of the dryer.
This object is achieved by a nozzle bottom arrangement with the features of patent claim 1 and by a method for operating the nozzle bottom arrangement with the features of patent claim 18.